It's clear to most political observers that the LibDem vote is being squeezed. Those who had gone to the LibDems because they had become disillusioned with Tony Blair are returning from whence they came, and going out the other door are those who find the new look Conservatives an attractive proposition. The inheritance tax announcement has attracted back many people to the Conservative tent, many of whom voted LibDem last time.
The LibDem polling performance now seems to be in the 11-15% area, whereas a few weeks ago it was 13-17%. How much lower can they go before the consider the nuclear option? I imagine the phonelines in the Clegg and Huhne households have been slightly busier than usual this weekend.